1. Field of the Invention
This invention relates to a pleated cartridge air filter in which the pleats are separated from each other by means of beads and which includes a reverse pulse cleaner for automatically cleaning the cartridge.
2. Description of the Related Art
Air filter units have been developed in the prior art, such as described in U.S. Pat. No. 5,512,086 issued Apr. 30, 1996 to Glucksman, which employ pleated filter elements. The use of pleats has a distinct advantage in that it affords considerably greater filtering area. It has been found, however, that the pleats tend to bend together towards each other and thus lose their effectiveness. To obviate this problem, separator elements have been employed to keep the pleated elements separated from each other. As mentioned in Glucksman, this can take the form of a glue or other such material placed between the pleats which when it hardens forms separating beads. Such a device is described in U.S. Pat. No. 5,071,555 issued on Dec. 10, 1991 to Enbom. It is to be noted that in Enbom, the filter is linear and not in the form of a container such as a cylinder. It is to be noted that in Glucksman, the cartridge is the form of a half sphere and is not in the form of a container having continuous side walls.
A problem which prior art devices have is the necessity to rather frequently replace the filter cartridges particularly where the surrounding air has considerable dirt to be filtered out. This not only involves the costs involved in installing new filters but also the possibility of not replacing the filter in time which results in dirty air being fed to the area where clean air is required. The device of the present invention solves this problem by providing automatic cleaning of the filter in response to a measurement indicating that the filter is overfilled with dirt.